Answer:
The first set of simultaneous equations.
x = 20 and y = 5
The second set of simultaneous equations:
x = -3 and y = -5
The third set of simultaneous equations:
x = -1 and y = -3
Step-by-step explanation:
The first set of simultaneous equations.
x - 2y = 10 ... (i)
x - 3y = 5 ... (ii)
Subtracting (i) - (ii) we get;
0 + y = 5
Hence y = 5 and,
x - 2(5) = 10
x = 10 + 10 = 20
The second set of simultaneous equations:
2x - 3y = 9 ... (i)
-5x - 3y = 30 ... (ii)
Subtracting (i) - (ii) we get;
7x + 0 = -21
7x = -21
x = -3
and,
2(-3) - 3y = 9
3y = -6 - 9
3y = -15
y = -5
The third set of simultaneous equations:
x + y = -4 ... (i)
x - y = 2 ... (ii)
Adding (i) - (ii) we get;
2x + 0 = -2
2x = -2
x = -1
and,
-1 - y = 2
y = -1 - 2 = -3
